1. Field of the Invention
The present invention relates to a solid-state camera, and more particularly relates to a solid-state camera which can provide fine picture images even under a backlight state.
2. Description of the Prior Art
FIG. 1 is a schematic diagram of a prior art solid-state camera or a video camera. Incident light is focused by a lens 1 on an image sensor face of a solid-state image sensor or a solid-state area sensor 2 to form an image. The solid-state area sensor 2 is composed of a plurality of semiconductor photoelectric conversion elements (picture element cells) which are planarly arranged on the plane image picture face. The solid-state area sensor 2 is driven by a pulse power source and direct current outputted from a driven means 3 and photoelectric conversion signals of a photoimage focused on the image sensor face are successively output to a signal processor means 4. And then electric signals as the photoelectric conversion signals from the solid-state area sensor 2 are processed and output as video signals by the processor means 4.
When such a conventional general video camera is used under a backlight, it is usually difficult to effectively take fine picture images. For example, when the video camera is used for taking scenes outside the window immediately after photographing the inside of a room, very strong light rays from the outside come into the image faceplate of the solid-state area sensor 2.
In this case, since the output of a portion corresponding to the light rays in the picture element cells composing the solid-state area sensor 2 is saturated, a picture image corresponding to the portion becomes white. Thus, it is difficult to clearly take scenes out of the window in such a case. To cope with the problem, an ordinary camera has an auto-iris mechanism for automatically adjusting or closing an iris of the lens to control the incident light. Accordingly, the camera having such an auto-iris mechanism can guarantee the photographing of scenes outside of the window. However, in contrast, the picture images in the room become dark and undistinguishable, respectively. Namely, it is difficult to clearly take picture images of both the outside and the inside of a room at the same time by such a camera.